"Dr. Avery was a true scientist with an insatiable curiosity and
a powerful and unremitting urge to discover the innermost
mechanisms of the biological facts that came under his
observations."

--Alphonse R. Dochez

Oswald Theodore Avery was born on 21 October 1877 in Halifax,
Nova Scotia, the second of three sons of Elizabeth Crowdy and
Joseph Francis Avery. A Baptist minister in England, Joseph
Avery and his wife emigrated to Canada in 1873. After
establishing himself as a well-respected pastor in Halifax, he
moved his family to New York City in 1887, where he was
appointed the pastor of the Mariner's Temple Baptist mission
church on the lower East Side. Each member of the family
participated in the church: Elizabeth was involved with
charities and the newsletter while young "Ossie" and his oldest
brother, Ernest, often played their clarinets on the church
steps to attract new attendees. Ernest died early in 1892, at
the age of eighteen, probably from tuberculosis. Several months
later, Reverend Avery also passed away. Following their deaths,
the then fifteen-year old Oswald assumed the paternal role for
his youngest brother, Roy, a part he would also play some years
later to his cousin, Minnie Wandell, who Roy often
affectionately referred to as "little sister."

After attending the New York Male Grammar School, Avery went to
the Colgate Academy and then Colgate University, where he
excelled in literature, public speaking, and debate. While at
Colgate, he was a classmate of Harry Emerson Fosdick, who would
become one of the most notable clergymen in America; it is
likely that when Avery started at Colgate he also intended to
enter the ministry. Avery received a BA in the humanities in
1900. For reasons that are not clear, and despite the absence of
any scientific background, after college Avery chose a career in
medicine and entered the College of Physicians and Surgeons in
New York. He received his medical degree in 1904.

Desiring greater intellectual stimulation and frustrated by his
inability to help some of his patients, Avery moved in 1907 to
laboratory work at the Hoagland Laboratory in Brooklyn, the
first privately endowed bacteriological research institute in
the country. Since the laboratory was also associated with a
Long Island hospital, Avery's duties included teaching courses
for student nurses. It was here that he acquired his best known
and most enduring nickname, "The Professor," which was often
affectionately shortened to "Fess." The Hoagland Laboratory's
director, Benjamin White, instructed Avery in laboratory
techniques and biochemistry. Avery initially worked on the
bacteriology of yogurt, but soon developed an interest in
tuberculosis after White suffered a severe case of the
infectious pulmonary disease. It was during this time that Avery
established what his biographer René J. Dubos called the pattern
of his career, the "systematic effort to understand the
biological activities of pathogenic bacteria through a knowledge
of their chemical composition."

Avery's work came to the attention of Rufus Cole, the director
of the Hospital of the Rockefeller Institute for Medical
Research, through one of his papers on secondary infections in
pulmonary tuberculosis. One of Cole's goals was to develop a
therapeutic serum--like that which had been developed for
diphtheria--for pneumonia, and to this end he asked Avery to
join the Hospital's pneumonia research program. Avery moved to
the Rockefeller Institute in 1913, where he focused most of his
research for the next thirty-five years on a single species of
pneumonia-creating bacteria, Diplococcus pneumoniae. There, he
worked with scientists that were widely recognized as being
among the elite in their fields, including Alphonse R. Dochez,
René Dubos, Harriett Ephrussi-Taylor, Michael Heidelberger,
Rebecca Craighill Lancefield, Maclyn McCarty, and Colin MacLeod.
His research career culminated in 1944, when, with McCarty and
MacLeod, Avery published his seminal paper proving that the
"transforming principle," or hereditary material, was DNA and
not protein as most scientists had assumed.

In the early 1940s Avery and McCarty, a colleague at the
Hospital, concentrated on the phenomenon of pneumococcal
transformation, in which "R-form" (non-virulent) pneumococcus
bacteria changed into the virulent "S-form" after killed S-form
bacteria were added to the culture. The changed bacteria were
identical in virulence and type to the killed bacteria, and the
changes were permanent and inheritable. Utilizing refined
versions of MacLeod's preparation techniques, Avery and McCarty
soon isolated active "transforming substance" from samples of
pneumococci, and found that the substance was deoxyribonucleic
acid, or DNA. In 1944, Avery, MacLeod, and McCarty published
their discovery in the Journal of Experimental Medicine. Their
conclusions in this paper were cautious, and they presented
several interpretations of their results. The phenomenon of
transformation, they wrote, was "interpreted from a genetic
point of view." Yet they also gave another interpretation, that
there might be an "analogy between the activity of the
transforming agent and that of a virus." They concluded that,
"Assuming that the sodium desoxyribonucleate and the active
principle are one and the same substance, then the
transformation described represents a change that is chemically
induced and specifically directed by a known chemical compound.
If the results of the present study on the chemical nature of
the transforming principle are confirmed, then nucleic acids
must be regarded as possessing biological specificity." Although
some of their peers initially questioned this conclusion, in
1952, Alfred Hershey and Martha Chase proved DNA was the
hereditary material through their work with a bacterial virus
(phage). In 1953, James Watson and Francis Crick determined the
double helix structure of DNA. Thus, Avery played an early and
critical role in the molecular revolution in biology.

Soon after starting at the Rockefeller Institute, Avery began to
share an apartment with Dochez, who was then a colleague in the
respiratory disease department at the Hospital. The two life-long bachelors continued as roommates for most of the following
thirty-five years. They made complementary housemates and
friends, as Avery was somewhat introverted and retiring whereas
Dochez was gregarious and outgoing. He would often return home
from a night out and engage Avery with his thoughts on an aspect
of microbiology which had occurred to him earlier in the
evening. Both men acknowledged that they derived a great deal
from these late night discussions. They used each other as
sounding boards for trying out new ideas or better defining
works in progress.

In the early 1930s, Avery underwent treatment for Graves'
disease. He took a brief leave from the Hospital in 1934
following a thyroidectomy, but did not fully recover for several
years. In 1943, at the mandatory retirement age of 65, Avery
became a member emeritus at the Rockefeller Institute; however
he continued his research there until 1948. He then moved to
Nashville to be closer to the family of his brother, Roy, a
bacteriologist at the Vanderbilt School of Medicine. Avery
rented a home down the street from Roy, and quickly became a
fixture in the neighborhood. Avery's cousin, Minnie Wandell, who
was very close with him, acted as his housekeeper. While
vacationing on Deer Isle late in the summer of 1954, Avery
experienced terrific pain in his abdomen, and subsequent surgery
revealed extensive cancer of the liver. He died in Nashville on
20 February 1955 at the age of 77.

Avery achieved many honors during his career. He served as
president of the American Association of Immunologists, the
American Association of Pathologists and Bacteriologists, and
the Society of American Bacteriologists. He was elected to the
National Academy of Sciences and the Royal Society of London. He
received honorary degrees from McGill University, New York
University, the University of Chicago, and Rutgers University,
as well as awards from organizations such as the Royal Society
of London, the American College of Physicians, the Association
of American Physicians, and the New York Academy of Medicine.
Avery received the Lasker Award in Basic Medical Research in
1947.

Brief Chronology

1877 --Born in Halifax, Nova Scotia (October 21); son of a clergyman

1887 --Avery family moves to New York City

1900 --Receives BA from Colgate University

1904 --Receives MD from the College of Physicians and Surgeons, Columbia University; practices medicine (general surgery) in New
York City

1907 --Appointed associate director of bacteriological department at the Hoagland Laboratory in Brooklyn, New York

1913 --Joins the Rockefeller Institute for Medical Research as an assistant

1915 --Promoted to an associate at the Rockefeller Institute

1917 --Becomes a private in the U.S. Army Medical Corps

1918 --Acquires U.S. citizenship

1918 --Commissioned as a captain in the U.S. Army

1919 --Becomes an associate member at the Rockefeller Institute for Medical Research

1923 --Becomes a member of the Rockefeller Institute

1932 --Receives John Philips Memorial Award from the American College of Physicians